Grinding wheel angle dresser

ABSTRACT

A grinding wheel dressing tool includes a generally L-shaped base block supporting a releasably held rotary member for establishing the angular direction of an associated rectilinearly slidable cutter-carrying member, the latter being manipulable while the tool is resting in any one of three positions. The structure is such that all bearing surfaces are made inaccessible to the abrasive dust attending operation.

United States Patent Foshee et al.

GRINDING WHEEL ANGLE DRESSER Inventors: Wayne 0. Foshee: Bruno J. Zapart, both of PO. Box l217, Hot Springs, Ark. 71901 Filed: June [7, 1974 Appl. No.: 479,700

Related [15. Application Data [63] Continuatiun-in-part of Ser. No. 342.821. March 14,

1973. abandoned.

[52] US. IZS/ll AT; 125/[1 B; l25/ll AT [5 l I Int. Cl B24b 53/12 [58] Field of Search .1 125/11 B, 11 AT, ll A l25/ll R 156] References Cited UNITED STATES PATENTS 2.369.405 21945 Pollard l25/1l AT [4 1 June 10, 1975 2402.945 7/1946 Brocket 125/11 B 2.458.768 1/1949 Daily 125/11 AT 2.479.101 8/1949 Dahl 125/11 AT 2.642.856 6/1953 Calloway 125/11 AT 2.726.650 12/1955 Failla 125/11 R 3,576,184 4/1971 Nichols 125/11 8 Primary Examiner-Har0ld D. Whitehead Attorney, Agent, or Firm-Ralph R. Pittman [57] ABSTRACT A grinding wheel dressing tool includes a generally L shaped base block supporting a releasably held rotary member for establishing the angular direction of an associated rectilinearly slidable cutter-carrying memher the latter being manipulable while the tool is resting in any one of three positions. The structure is such that all bearing surfaces are made inaccessible to the abrasive dust attending operation,

6 Claims, 8 Drawing Figures GRINDING WHEEL ANGLE DRESSER This application is a continuation-in-part of applicants copending application Ser. No. 342,82l, filed Mar. 14, l973 and now abandoned.

BACKGROUND Grinding wheel dressing tools described in the prior art are many in number and varied in structure, ranging from small hand tools to highly complex and expensive motor-driven radius and tangential forming mecha' nisms embodied as an integral component of a grinding machine.

In general, the hand-operated prior art angle wheel dressers require several mechanical operations to adjust the tool to effect more than a single angle cut on a wheel, and the reduction of unproductive adjustment time is important in reducing the cost of machine work.

Relatively low-cost manually operable angle dressers heretofore described are more or less susceptible to the penetration or direct deposition of abrasive dust on such parts as the rotary bearings, the slide bearings and the index wheel, if any. Such deposits not only require lost time for frequent cleaning but, more importantly, the abraded engaging members prevent the attainment of the desired precision in the shape of the wheel grinding surface due to vibration of the cutting member.

SUMMARY OF THE INVENTION The grinding wheel dressing tool described herein utilizes a base block which is L-shaped in section. A rotatably adjustable carrier disk is journaled in an annular ring fixed in the wall of the base, and a cylinder block is rigidly fixed to the carrier disk and rotatable therewith. A piston, rectilinearly movable in the cylinder block, projects downwardly through a slot along the underside of the cylinder block and a cutter holder is fastened to the underside of the piston, projecting forwardly, upwardly and rearwardly therefrom. A cutter, preferably diamond-tipped, projects upwardly from the top of the cutter holder.

A locking knob is threaded on a rearwardly projecting portion of the carrier disk, cooperating with an interposed cupped spring washer for locking the rotatably adjustable carrier disk in a selected angular position. indicia along the circumferential face of the carrier disk are visible in a transparent viewing aperture in the annular mounting ring to observe the annular position of the disk.

The structure effectively shields all bearing surfaces from contact with grinding wheel particulates, thus precluding abrasive damage to the slidable elements of the dresser; also, the angle-indicating marks along the face of the cutter carrier disk cannot be obscured by the dust attending the operation of the tool.

In addition to the rotatably adjustable and linearly movable cutter above mentioned, a pair of stationary cutters are mounted to project outwardly from the respective upper corners of the upstanding wall of the base.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view, a portion of the ring bearing being broken away to show the annular indicia marks; the broken lines show the positions to which the movable cutter holder may be moved;

FIG. 2 is a front elevation, the broken lines showing the arcuate path along which the cutter may be selectively locked;

FIG. 3 is a fragmentary side elevation, the sections being principally taken along the lines 33 of FIG. I, showing the internal elements in their assembled relation;

FIG. 4 is an enlarged fragmentary view showing the window in the wall of the ring bearing which enables the internal indicia along the peripheral face of the carrier disk to be observed while the movable cutter is being adjusted to an specific angular direction;

FIG. 5 is an enlarged fragmentary view of the structure for both guiding the reciprocable piston and compensating for wear;

FIG. 6 shows the dresser positioned on its foot plate for cutting a grinding wheel at a relatively large angle with respect to the plane of rotation;

FIG. 7 shows the dresser resting on its base after being turned in one direction through an angle of for cutting a grinding wheel at a relatively small angle and FIG. 8 shows the dresser turned 90 in the other direction for cutting the other side of the wheel at a small angle.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drawing illustrates a rotatably adjustable and rectilinearly movable cutter mounted upon a base block, L-shaped in section, which includes the foot plate 10 to which is joined along one margin the upstanding leg or wall plate 11. The base plates 10 and 11 are rectangular prisms of equal length and the base block may be formed either in one piece or by joining the plates. The respective ends of the L-shaped base block are disposed in parallel planes normal to the planar underside of the foot plate 10, the dresser being structured to function from any one of three positions; namely, when rested either solely on the foot plate or when rested on either L-shaped end surface.

A ring bearing 12 is rigidly secured in the wall 11 by the fastener 13, the axis ring bearing being located equidistantly from (I) the respective ends of the wall II and (2) the lower surface of the foot plate 10.

A circular carrier disk 14 is journaled for rotary movement within the ring bearing 12, the disk 14 having a hollow externally and internally threaded portion 15 projecting rearwardly from its midsection. A locking knob 16 threadedly engages the external threads along the projection 15. A cupped spring washer 17 is fitted into an annular recess in the rear wall of the ring bearing 12, the Washer 17 being interposed between the knob 16 and resiliently movable against the rearward face of the disk in response to a predetermined forward movement of the knob I6 to thereby restrain the disk 14 from rotary movement.

A cylinder block 18 is rigidly fixed to the rotatable disk 14 by the fasteners 19, the cylinder block extending longitudinally along the disk 14, the bore of the cylinder being truncated along the underside to provide a longitudinally extending opening along a portion of the forward wall and the underside of the cylinder block.

A piston 25 is slidably fitted into the cylinder block 18 for reciprocal motion therealong, and a guide and wear adjustment rod 20 threadedly engages the internal threads along the projection l5, extending forwardly therefrom through the adjacent block wall to engagement with the piston 25.

As the enlarged view at FIG. 7 shows, the linear guide slot 27 is provided with outwardly diverging walls, and a tapered end portion 21 of the rod is slip-fitted into and only partially fills the slot 27, the space 37 being available for wear adjustment. A suitable angle of divergence is of the order of eight degrees.

A portion of the underside of the piston 25 is flattened, to facilitate the rigid attachment thereto, by the fastener 26, of the lower arm of the U-shaped movable cutter holder 22.

The lower arm of the cutter holder extends first forwardly from the piston to a point beyond the forward wall of the cylinder block 18, thence upwardly therealong to an elevation above the cylinder block and thence rearwardly in spaced relationship with the upper surface of the cylinder block and with the ring bearing 12. A manipulating handle 28 projects forwardly from the bight portion of the cutter holder 22 to enable convenient reciprocal manipulation of the upwardly directed grinding wheel cutter 23. The cutter element 23, which is preferably diamond-tipped, is slipfitted through an aperture near the end of the upper arm of the U-shaped cutter holder 22 and fixed thereto by the set screw 29. The space indicated at the numeral 24 between the upper surface of the cylinder block 18 and the cutter holder 22 provides for deposition of a substantial layer of abrasive dust along the top of the cylinder block without interfering with the reciprocal movement of the carrier during a dressing operation.

As indicated in FIG. 1, the circumferential face of the rotatable carrier disk 14 is provided with the angle degree marks 34, which are viewable through the radially directed aperture 33. An enlargement of this portion of the structure appears at FIG. 4, showing the aperture 33 filled with a transparent plug 35, across the lower end or inner face of which an indicia mark is placed, for registration with the marks along the carrier disk 14.

For use in establishing extremely high degree of precision in angle settings, the sine pins 30 project forwardly from the rotatable cylinder block, being laterally located an equal distance from its axis of rotation. These pins are adapted to engage sine blocks of known dimensions which rest on the foot plate, in a manner well known in this art.

In addition to the rotatably settable and slidably mov able cutter 23, a pair of stationary cutters 32 are removably mounted at the respective upper corners of the wall plate 11, each projecting laterally therefrom for a distance equal to that of the other, these cutters being mounted in the L-shaped holders 3] and removably attached to the wall plate 11 by the fasteners 36.

The stationary cutters enable the sides of a grinding wheel to be dressed to a vertical plane by simply moving the wheel vertically while in contact first with one stationary cutter until one side is plane, and repeating the operation on the other side of the wheel with the other stationary cutter.

For shaping the abrading edge or face of a grinding wheel, the locking nob 16 is first loosened, releasing the carrier disk 14 for rotary movement in the ring bearing. The rotatable cutter assembly which includes the cylinder block 18 and the cutter holder 22 may then be turned to the desired angular position. The locking knob 16 is then tightened against the pressureresponsive spring Washer 17 to rigidly lock the rotatable assembly. The cutter holder 22 is then manually moved rectilinearly to direct the cutter 23 across the face of the grinding wheel at the pre-set angle, the grinding wheel being in rotation during the dressing operation.

It may be noted that all slidably-engaged surfaces are completely shielded from the abrasive dust which necessarily accompanies wheel dressing, the cylinder block effectively shielding the interface between the piston and the internal surface along the cylinder bore, and the bearing ring completely enclosing the interface between the rotary carrier disk and the inner circumfen ential ring bearing surface. If, after long use, the appearance of vibration of the cutter signals that the piston has slightly loosened in the cylinder by wear, a fractional turn of the guide and wear adjustment rod 20 will modify the degree of sliding engagement and thereby eliminate the vibration.

The versatility of this angular dresser is indicatd and partially illustrated at FIGS. 6, 7 and 8. FIG. 6 shows the dresser resting on its foot plate in position to dress the grinding wheel 38 at a relatively large angle with respect to its vertical sides. FIG. 7 shows the dresser in a first alternate position, resting on the coplanar edges of the foot and leg plates at one end of the L-shaped base, for dressing one side of the grinding wheel at a small angle with respect to the vertical side, and FIG. 8 illustrates the second alternate position of the dresser, similar to that of FIG. 7, except turned 180 for a small angle dressing operation at the opposite side of the grinding wheel.

It is the specified location and orientation of the carrier disk with respect to the planar bottom surface of the base plate and the planar L-shaped ends of the base block that enables angular adjustments of the cutter direction to be effected by simply turning the base block bodily about the axis of the carrier disk. With the structure herein described, one quickly-made adjustment of the cutter assembly is all that is required for setting the dresser to cut at any angle from zero to 90 with respect to the plane of rotation of the grinding wheel. and it is believed obvious that the respective sides of a grinding wheel may be dressed along either equal or widely differing slopes.

What is claimed is:

1. In a grinding wheel angle dressing tool having an upstanding wall plate, a ring bearing fixed in the wall plate, a rotatable carrier disk journaled in said ring bearing and locking means for selectively precluding rotatable movemtnt of said carrier disk, the improvement comprising a cylinder block rigidly secured to the forward side of said disk and rotatable therewith,

said cylinder block extending transversely across said disk and a linear longitudinally extending slotted opening disposed along the underside of said cylinder block,

a reciprocally movable piston within said cylinder,

a U-shaped cutter holder movable with said piston,

said cutter holder straddling said cylinder block from the forward side thereof,

the lower arm of said cutter holder being rigidly secured to the underside of said piston and extending forwardly in slidable engagement with the underside of said cylinder block and the upper arm of said cutter holder extending rearwardly over and above the top of said cylinder block,

a manipulating handle projecting forwardly from the bight of said U-shaped cutter holder and a grinding wheel cutter projecting outwardly from the upper arm of said cutter holder.

2. The tool as set forth in claim 1, including a pair of laterally spaced sine pins projecting forwardly from the forward wall of the cylinder block in spaced relation with the upper surface of said base plate, said pins being equally spaced from the axis of said disk and positioned in a plane passing diametrically through said disk.

3. The tool as claimed in claim 1, wherein the lower arm of said U-shaped cutter holder is rectangular in section and said piston is flattened along the underside at the juncture of said lower arm with said piston.

4. A grinding wheel angle dressing tool comprising an L-shaped base including a rectangular base plate and an upstanding wall plate, a ring bearing fixed in the wall plate, a rotstable carrier disk journaled in said ring bearing, said disk having a concentrically disposed externally threaded projection extending rearwardly therefrom, a resiliently-deformable washer surrounding said projection, an annular portion of said washer abutting said ring bearing, a locking knob threadedly engaging said projection and movable to engage and compress said washer against said bearing ring, a cylinder block rigidly attached to the forward side of said disk and rotatable therewith, said cylinder block extending transversely across said disk and having a linearly extending opening along the underside thereof, a reciprocally movable piston within said cylinder. a U-shaped cutter holder straddling said cylinder block from the forward side thereof, the lower arm of said cutter holder being rigidly secured to the underside of said piston and reciprocally movable therewith, a grinding wheel cutter projecting outwardly from the upper arm of said U-shaped cutter holder, a manipulating handle projecting forwardly from the bight of said U-shaped cutter holder, an axially directed bore extending forwardly through said carrier disk from the rearward end of said externally threaded projection, a coextensive aperture in the wall of said cylinder in registration with said bore, a linearly extending slot along the rearward side of said piston in registration with said aperture during reciprocal movement of the piston, a guide rod extending coaxially within said bore and through said aperture to engagement with said piston along said slot, the rearward end portion of said rod engaging internal threads along a rearward end portion of said axial bore.

5. The tool in accordance with claim 4, wherein the walls of the linear slot along the piston diverge with respect to the axis of the rod and the associated end of the rod engages said piston only along the diverging walls of said slot.

6. A grinding wheel angle dressing tool comprising an L-shaped base including rectangular base and wall plates of equal length, an arcuate cavity defined by the sector of a circle greater than a semicircle extending downwardly from the top of said wall plate, the center of said circle being located at a point equidistant from the bottom surface of said base plate and the respective lateral edges of said wall plate, a circular bearing ring mounted in said cavity, said bearing ring having a portion thereof defining an arc of less than projecting above the top of said wall plate, a carrier disk journaled in said ring, rectilinearly movable cutter means rotatably supported from said disk, indicia means indicating the angle of departure from the vertical of the direction of movement of said cutter means, said indicia being disposed along the circumferential face of said disk, viewing means associated with said bearing ring for observing the indicated angle, said viewing means including an aperture in said ring, said aperture being radially directed at an angle of 45 from the top of said ring and containing a dust-tight closure of transparent material, an indicating mark along the lower face of said closure, and clamping means effective to lock said carrier disk at a selected angular position 

1. In a grinding wheel angle dressing tool having an upstanding wall plate, a ring bearing fixed in the wall plate, a rotatable carrier disk journaled in said ring bearing and locking means for selectively precluding rotatable movemtnt of said carrier disk, the improvement comprising a cylinder block rigidly secured to the forward side of said disk and rotatable therewith, said cylinder block extending transversely across said disk and a linear longitudinally extending slotted opening disposed along the underside of said cylinder block, a reciprocally movable piston within said cylinder, a U-shaped cutter holder movable with said piston, said cutter holder straddling said cylinder block from the forward side thereof, the lower arm of said cutter holder being rigidly secured to the underside of said piston and extending forwardly in slidable engagement with the underside of said cylinder block and the upper arm of said cutter holder extending rearwardly over and above the top of said cylinder block, a manipulating handle projecting forwardly from the bight of said U-shaped cutter holder and a grinding wheel cutter projecting outwardly from the upper arm of said cutter holder.
 2. The tool as set forth in claim 1, including a pair of laterally spaced sine pins projecting forwardly from the forward wall of the cylinder block in spaced relation with the upper surface of said base plate, said pins being equally spaced from the axis of said disk and positioned in a plane passing diametrically through said disk.
 3. The tool as claimed in claim 1, wherein the lower arm of said U-shaped cutter holder is rectangular in section and said piston is flattened along the underside at the juncture of said lower arm with said piston.
 4. A grinding wheel angle dressing tool comprising an L-shaped base including a rectangular base plate and an upstanding wall plate, a ring bearing fixed in the wall plate, a rotstable carrier disk journaled in said ring bearing, said disk having a concentrically disposed externally threaded projection extending rearwardly therefrom, a resiliently-deformable washer surrounding said projection, an annular portion of said washer abutting said ring bearing, a locking knob threadedly engaging said projection and movable to engage and compress said washer against said bearing ring, a cylinder block rigidly attached to the forward side of said disk and rotatable therewith, said cylinder block extending transversely across said disk and having a linearly extending opening along the underside thereof, a reciprocally movable piston within said cylinder, a U-shaped cutter holder strAddling said cylinder block from the forward side thereof, the lower arm of said cutter holder being rigidly secured to the underside of said piston and reciprocally movable therewith, a grinding wheel cutter projecting outwardly from the upper arm of said U-shaped cutter holder, a manipulating handle projecting forwardly from the bight of said U-shaped cutter holder, an axially directed bore extending forwardly through said carrier disk from the rearward end of said externally threaded projection, a coextensive aperture in the wall of said cylinder in registration with said bore, a linearly extending slot along the rearward side of said piston in registration with said aperture during reciprocal movement of the piston, a guide rod extending coaxially within said bore and through said aperture to engagement with said piston along said slot, the rearward end portion of said rod engaging internal threads along a rearward end portion of said axial bore.
 5. The tool in accordance with claim 4, wherein the walls of the linear slot along the piston diverge with respect to the axis of the rod and the associated end of the rod engages said piston only along the diverging walls of said slot.
 6. A grinding wheel angle dressing tool comprising an L-shaped base including rectangular base and wall plates of equal length, an arcuate cavity defined by the sector of a circle greater than a semicircle extending downwardly from the top of said wall plate, the center of said circle being located at a point equidistant from the bottom surface of said base plate and the respective lateral edges of said wall plate, a circular bearing ring mounted in said cavity, said bearing ring having a portion thereof defining an arc of less than 180* projecting above the top of said wall plate, a carrier disk journaled in said ring, rectilinearly movable cutter means rotatably supported from said disk, indicia means indicating the angle of departure from the vertical of the direction of movement of said cutter means, said indicia being disposed along the circumferential face of said disk, viewing means associated with said bearing ring for observing the indicated angle, said viewing means including an aperture in said ring, said aperture being radially directed at an angle of 45* from the top of said ring and containing a dust-tight closure of transparent material, an indicating mark along the lower face of said closure, and clamping means effective to lock said carrier disk at a selected angular position. 